1. Genetic and Management Methods to Improve Reproductive Efficiency inSowsAllen D. Leman Swine Conference: Pre-Conference Program University of Alberta-University of MinnesotaReproduction Workshop: 12 - September - 2012 Ken Stalder, PhDProfessor & Extension Swine SpecialistIowa State University, AmesIOWA STATE UNIVERSITYDepartment of Animal Science

2. Introduction Pork producer profits are constrained Increased feed costs Increased labor costs Increased regulatory issues Areas where production efficiency can beimproved should be continually evaluated. Remain competitive with other protein foodsources Remain competitive with other producers world-wideIOWA STATE UNIVERSITYDepartment of Animal Science 3. Increased Cost of Production Feed costs have impacted pork productionin many ways. Grow finish cost of production Gilt development costsIf feed costs had remained low and price high Positive NPV attained within P1 or P2Increased feed costs Positive NPV attained ~ P3 Really high feed costs Positive NPV will not be attained untilfeed costs decline or market price increasesIOWA STATE UNIVERSITYDepartment of Animal Science 4. Sow Longevity Value Commercial producers and geneticsuppliers are recognizing the value of sowlongevity. Value of retaining sows in the breeding herd for agreater number of parities. Many contributing factors leading to a sowleaving the breeding herd earlier than farmmanagement desires.IOWA STATE UNIVERSITYDepartment of Animal Science 5. Complexity of Sow Length of ProductiveLife Involvement of Genetics Environmental Caretaker skills or stockmanship Gilt development Gilt conformation Fecundity Nutrition Gilt development Gestation Lactation Health Housing Pen vs. crated environment Flooring Behavior Seasonal effects Cull sow market priceIOWA STATE UNIVERSITYDepartment of Animal Science 6. Introduction Many of these topics are not wellresearched particularly when modernhousing systems and genetics are takeninto consideration.IOWA STATE UNIVERSITYDepartment of Animal Science 7. Incidence of failure to breed, lameness and culling for old age, in the sows according to litter parityDagorn & Aumaitre, 1978 10090 Similar findings have been Cumulated percentage of culled sowsreported in a more recent8070605040popular press article in the3020US10 0 Conclusion very similar tothose previously presented 1 23456 7 8910 >10Number of litters per sow Failure to breed Lameness Old Age Other Challenging data Retrospective data Reported vs real reason sows are removedIOWA STATE UNIVERSITYDepartment of Animal Science 8. Characterization of U.S. Midwestern cull sows Examined > 3,100 cull sows at harvest Obtained data from two harvest plants Farm production data from ~ 1,000 animalsavailable Objective Characterize physical and reproductiveconditions of cull sows from U.S. Midwestern sowharvest plantsIOWA STATE UNIVERSITYDepartment of Animal Science 9. U.S. cull sow study- data collection Traits measured Foot lesions (presence or absence) Front pad lesions Rear pad lesions Front cracked toes Rear cracked toes Front digital overgrowth Rear digital overgrowth Front missing dew claws Rear missing dew claws Front abscesses Rear abscessesIOWA STATE UNIVERSITYDepartment of Animal Science 10. U.S. cull sow study- results Pad lesions- rear 67.5%, front 32.9%IOWA STATE UNIVERSITYDepartment of Animal Science 11. U.S. cull sow study- results Cracked toes- front 22.6%, rear 18.1%IOWA STATE UNIVERSITYDepartment of Animal Science 12. U.S. cull sow study- results Sows with front cracked toes compared tosows without tended (P = 0.07) to havefewer pigs born alive/day/herd life (0.0703vs. 0.0725) equates to ~0.8 pigs/sow/yearIOWA STATE UNIVERSITYDepartment of Animal Science 13. U.S. cull sow study- results Digital overgrowth- rear 21.1%, front 3.5%IOWA STATE UNIVERSITYDepartment of Animal Science 14. U.S. cull sow study- resultsIOWA STATE UNIVERSITYDepartment of Animal Science 15. U.S. cull sow study- results Sows with rear digital overgrowth incomparison to sows without had fewer (P < 0.05) pigs born alive in last litter (0.54) tendency (P = 0.06) for decreased pigs bornalive/day/herd life (0.0702 vs. 0.0724) equates to ~0.80 pigs/sow/yearIOWA STATE UNIVERSITYDepartment of Animal Science 16. U.S. cull sow study- results Traits measured reproductive tract evaluation ovary statusnormal- 84.7%acyclic- 9.0%cystic-6.3% pregnant-5.9%IOWA STATE UNIVERSITYDepartment of Animal Science 17. U.S. cull sow study- resultsIOWA STATE UNIVERSITYDepartment of Animal Science 18. U.S. cull sow study- results Traits measured shoulder lesions none-82.7% abrasions- 12.5% open wounds- 4.8%IOWA STATE UNIVERSITYDepartment of Animal Science 19. U.S. cull sow study- resultsIOWA STATE UNIVERSITYDepartment of Animal Science 20. U.S. cull sow study- results Sows with shoulderlesions had 2.01 fewer(P < 0.05) lifetime pigsborn alive comparedto sows withoutshoulder lesionsIOWA STATE UNIVERSITYDepartment of Animal Science 21. U.S. cull sow study- results Traits measured Systematic lesions Pneumonia- 9.7%1-10% lung involvement from pneumonia- 5.0%10% lung involvement from pneumonia- 4.7% Pleural adhesions- 5.6% Peritonitis- 1.7% Other- < 1%IOWA STATE UNIVERSITYDepartment of Animal Science 22. U.S. cull sow study- resultsIOWA STATE UNIVERSITYDepartment of Animal Science 23. U.S. cull sow study- results A higher percentage of lung involvementfrom pneumonia tended (P < 0.10) to beassociated with higher producing sows(lifetime pigs born alive, pigsborn/day/herd life)IOWA STATE UNIVERSITYDepartment of Animal Science 24. U.S. cull sow study- results Traits measured Teeth top teeth number bottom teeth number wearminimum- 10.5%moderate- 47.0%severe- 42.5%IOWA STATE UNIVERSITYDepartment of Animal Science 25. U.S. cull sow study- resultsIOWA STATE UNIVERSITYDepartment of Animal Science 26. U.S. cull sow study- results Sows with severe teeth wear incomparison to sows without had fewer (P = 0.06) pigs born alive in last litter (0.44) fewer (P < 0.01) pigs born alive/day/herd life(0.0704 vs. 0.0734) equates to ~1.1 pigs/sow/yearIOWA STATE UNIVERSITYDepartment of Animal Science 27. U.S. cull sow study- culling reasonsParity 1,23,45,67,89+Farm culling coden= 198 n= 145 n= 219 n= 201 n= 160Body condition, % 11.6 (2)a 15.2 (3) 9.6 (5)7.5 (3)5.6 (3)Old age, % 1.5 (6)4.1 (6)21.5 (2) 65.7 (1) 83.8 (1)Lameness, %10.6 (3) 17.9 (2) 11 (4) 5.5 (4)0.6 (6)Other, % 7.1 (4)10.3 (4) 8.2 (6)5.5 (4)1.3 (5)Poor litter performance, % 6.1 (5)6.2 (5)19.6 (3) 2.5 (6)2.5 (4)Reproduction, %63.1 (1) 46.2 (1) 30.1 (1) 13.4 (2) 6.3 (2)aRank of culling code within parity group.IOWA STATE UNIVERSITYDepartment of Animal Science 28. U.S. cull sow study- reproductive failure No heat most frequent farm culling code in parity 1 (41.1%) Did not conceive most common in parities 2 to 5 (39.2, 36.5, 25.4, and 27.4%, respectively) Of the sows culled for reproductive failure, 86.2% were classified as having normal ovariesIOWA STATE UNIVERSITYDepartment of Animal Science 29. U.S. cull sow study- summary U.S. cull sows evaluated at harvest had foot,reproductive, shoulder, and systemic lesions Body condition was associated with multipleabnormal conditions of sows Several conditions were associated with reducedsow performance parameters (lifetime pigs bornalive, pigs born alive in last litter, pigs bornalive/day/herd life) The majority of low parity sows were culled forreproductive failure, but ovaries were normal inappearanceIOWA STATE UNIVERSITYDepartment of Animal Science 30. Genetic Effects on Sow Longevity Study designed to estimate thephenotypic and genetic associations ofgilt compositional and structuralsoundness traits with reproductive andlongevity traits Determine factors measured or evaluatedearly in a sows life that are associatedwith superior sow productive lifetime. Data collected through at least parity 5IOWA STATE UNIVERSITYDepartment of Animal Science 31. Genetic Effects on Sow Longevity The study involved 1447 females from twocommercially available genetic lines. Gilts were on average 190 days of age and124 kg body weight at the time of bodycomposition and structural soundnessevaluation. National Pork Board Funded projectIOWA STATE UNIVERSITYDepartment of Animal Science 32. Genetic Effects on Sow Longevity Traits evaluated Compositional traitsBody weight,Loin muscle area,10th rib backfat, andLast rib backfat.IOWA STATE UNIVERSITYDepartment of Animal Science 33. Genetic Effects on Sow LongevityIOWA STATE UNIVERSITYDepartment of Animal Science 34. Genetic Effects on Sow Longevity Reproductive traits evaluated Lifetime total number born, Lifetime number born alive, Number born alive per lifetime days, and Percentage productive days from total herd days. Lifetime, herd days and removal parity were considered aslongevity traits.IOWA STATE UNIVERSITYDepartment of Animal Science 35. Means and heritability estimates for lifetime reproduction traits in study evaluating the relationship between compositional, structural soundness, reproductive performance and productive lifetime in commercial lines of sows. REML Mean s.e.Mean s.e. P-valueah s.e.Lifetime reproductionAcross genetic Grandparent line Parent linelinesLifetime total numberborn 40.94 1.7446.01 1.31 0.040.16 0.06Lifetime number bornalive37.71 1.6241.17 1.14 0.040.17 0.06LBA/Lb0.040 0.036 0.0010.001 0.005 0.16 0.06PD%c 58.22 1.4862.79 0.95 0.010.14 0.06IOWA STATE UNIVERSITYDepartment of Animal Science 36. Genetic Effects on Sow Longevity ~ 70% of the females were removed prior to the sixth parity. At the termination of data collection, 14% of the females were still alive and in production at the commercial sow herd. Reproductive failure was the most frequent culling reason during the first three parities and it caused the loss of 16% of the research females before the fourth parity. Culling for lameness or feet and leg problems primarily occurred prior to the third parity causing the removal of 7.5% of the young females.IOWA STATE UNIVERSITYDepartment of Animal Science 37. Genetic Effects on Sow Longevity Heritability Estimates Longevity traits 0.12 to 0.16 Lifetime reproduction traits 0.13 to 0.17 Compositional traits 0.50 - 0.70 Body structure traits 0.11 - 0.34 Leg structure traits 0.07 - 0.29 Greatest heritability estimates were obtained for weak front and rear pastern postures 0.28 and 0.29, respectively. Overall leg action 0.12IOWA STATE UNIVERSITYDepartment of Animal Science 38. Genetic Effects on Sow Longevity Genetic Correlation Estimates Most were low and non-significant (P > 0.05) Larger loin muscle area was significantlyassociated with greater lifetime, removalparity and lifetime number born Less upright rear legs were associated withgreater lifetime born alive per day of life andpercentage of productive days andintermediate rear foot size with greaterlifetime and removal parities.IOWA STATE UNIVERSITYDepartment of Animal Science 39. Sow Longevity and Genetic Progress Relationship Replacement and culling decisions should not be influence by the genetic progress occurring in the maternal lines from their genetic supplier. Under the most optimistic genetic improvement situations, a sow would not be replaced until the 6 th or 7th parity. This represents the parities where the value of the genetic progress that has occurred for maternal and growth traits is equal to or greater than the gilt development variable costs.IOWA STATE UNIVERSITYDepartment of Animal Science 40. Sow Longevity and Genetic Progress Relationship The parity at which gilt development variable costs and the genetic progress value are equal defines the number of parities that commercial breeding herds should cull sows for old age. Under realistic genetic improvement values, the cumulative value for the genetic improvement made across the traits is equal to the gilt development costs to at least the 10th parity or greater. Genetic issues should not enter into culling / replacement decisions for breeding herd sowsIOWA STATE UNIVERSITYDepartment of Animal Science 41. Summary Many factors contribute to the ability of asow to have a long and productive herdlife. These factors include genetic andenvironmental issues. A renewed focus on sow nutritionresearch is warranted.IOWA STATE UNIVERSITYDepartment of Animal Science 42. Summary Many traits genetically correlated withsow productive lifetime and can beimproved through selection. We cannot ignore the people factor on anyproduction process including porkproduction. Caretaker skills / stockmanship /management ability, effects on the sowproductivity cannot be underestimated.IOWA STATE UNIVERSITYDepartment of Animal Science